Wind energy is the fastest-growing electricity-generating technology. The wind energy targets set during the last decade have all been surpassed. Climate change is a major challenge to sustainable development worldwide and is increasingly recognized by forward-looking political and business leaders. One of the tasks we are facing is a profound transformation of our energy system over the next few decades of replacing fossil fuels with renewable energies and dramatically increasing energy efficiency. This article reviews the progress made by wind energy in recent years, and discusses the potential of this technology in the world. The Denmark and Germany experience has shown that wind energy today comprises a reliable and cost-effective technology with positive effects on the reduction of CO2 emissions.